Pneumatic damper-operating mechanism.



Patented Aug. 16, 1911.

L. B. DOMAN. PNEUMATIC DAMPER OPERATING MECHANISM.

APPLICATION FILED MAR 1S, 1906.

' To all whom it may concern:

LEWIS YB. DOMAIN, OF ELBRIDGE, NEW YORK.

PNEUMATIC DAMPER-OPERATING MECHANISM.

Specification of Letters Patent.

Patented Aug 15, 1911,

Application filed March 13, 1906. Serial No. 305,762.

v Be it known that I, LEWIS B. DOMAN, of r lulbridge, 1n the county of ()nondaga, 1n the State of New York, have 1nventednew and useful Improvements in Pneumatic Damper- Operatnig Mechanism, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to improvements in self-playing musical instruments, having particular reference to a pneumatic damperoperating mechanism whereby the damper operating pedal, and in fact, either of the other pedals ot a piano may be held in its active position for any period of time independently of the foot.

My ob jCCb is to provide pneumatic moans controlled by the linger of the operator for opc'iating a damper or other pedal-operated device used in connection with a mus' "al instrument, such as apiano and holding such damper in operating )osition. ln the drawings l have shown. a portion of a pneumatic self-playing musical instrument embodying the. various features of my invention, which consists essentially of a damper sustaining pneumatic -1- having its movable side attached or pivotally connected by a pin --2 to a reciprocatory rod I which latter is connected to and usually actuated by a pedal l.- for operating a damper or equivalent device used in c mncction ith the strings as t3--, of a piano or similar instrun'icnt.

inter or of the pneumatic li no connected by a passage -7 and conduit 8- to a \viml-chcstwhich in turn ishconncctcd either lire(-tly or imln'i-ctly to a \vi1'ulinducing device it) for main lai ning a partial vacuum in the exhaust chamber, a ----l 1- o't the wind-chest 9- lhis wind-rlurst 9 conlains a secondary pneumatic l3-- and a valve litplaying in a valvo-chambia' -l-l----- bclu'oon opposite ports 15 and. 1t'5--. The port sorvcs tomonncct the oxhaust-chanibor 1 l--- with the valvc-cbamher l l--- and is norn1ally-closcd by the valve l dwhile the port, 1lS-- opens to at.- n'iospl'icrc and serves to admit atmospheric air through the conduit. -7-- into the pneumatic ---1--- to distend.

the latter when the valve 13-- closes the port'15. ln the same wind-chest 4 is a second exhaust-chamber -17 which 18 8 and passage also connected directly or indirectly with the wind-inducing device -10-- and communicates through the port -18- with a valve-chamber 19, the latter chamber opening to atmosphere through a suitable port 20-.

A valve 21-plays between the ports 18 and 20 and is normally actuated to close the port -20- by a primary pneumatic 22- which is normally open to atmosphere through a conduit 23 and apertured finger-piece --24.-.

It is now obvious that as long as the pneumatic +22 is open to at-mos )here it will be distended to operate the va ve -2.1 to open the port -l8- and close the port 20-*, thereby establishing communication between the exhaust device 10 and pneumatic 12 through a passage --25--, the pneumatic 12 being somewhat larger in area than'the pneumatic 22 and by establishing communication between the exhaust-device 10 and pneumatic 1:2 the air tension in such pneumatic will be. the same as that in the chamber 11, and therefore, the inequality of pressure of atmosphere upon the valve 13- will operate to close the port 15- and to open the port -16 to allow atmospheric air to normally enter and distend the pedal operating pneumatics l ()n the other hand, if the operator places his finger over the opening -24i, thereby cutting oil atmospheric communication with the primary pneumatic -22 such pneumatic will be instantly deflated through a suitable bleed-hole therein, thereby allowing the valve -21 to open the port --20- and close the port '48 to allow atmospheric air to elite and distcnd the primaly pneumatic l2-. This distention ot' the primary pneun'iat-ic 'lr2- operates the valve 13- to close the port 10*, and to open the port --15- so as to establish communication between the exhaustchan'ibcr ll. and the damper-operating pneumatic --l--, whereupon the latter pneumatic is immediately de lated, thereby clcval ing the damper-rod --3- to withdraw tho damper -"5 from the string 6-, which parts are held in inoperative position as long as the operator keeps his finger upon the air inlet 2%.

As soon as the finger is removed i'i'oni the air inlet -2lthe inrush of atmospheric air through the tube 23" causes distention of the pneumatic 22 to re store the valve,21 to its normal position, closing the port 20 and again establishing communication between the exhaust chamber -17 and primary pneumatic 12 to deflate the latter and allow the valve 13- to close the port 15 and open communication between the damper-operating pneumatic ---1--- and atmosphere, whereupon said damper-operating pneumatic is distended and operates the damper rod -3- to allow the damper -5- to again contact with the strings The pneumatic -1 is mounted directly upon the under side of the key-board, as a-, of the piano, and is connected di rcctly to the damper rod 8, thereby avoiding the use of the intermediary levers, and affording direct action upon the damper.

It will be observed that the pneumatic --1 is controlled by the interruption of the current of air through the writ stand conduit 23- to the primary pneu matic 22--.

What i claim:

1. A device 01' the class described comprising in combination with a piano string, a damper, an operating pneumatic having a movable side and normally distended by comnuu'iication with the atmosphere, avertical damper rod directly connected to said movable side and having the damper seated upon the upper end thereof, a horizontally positioned wind chest having a chamber therein, a secondary pneumatic in said chamber at one side of said chest, opposite ports in the walls of said chamber, a valve operated by said secondary pneumatic be one side of said chest protween said ports,

a smaller chamber, a primary vidcd with l l l l l i i l l a l i l l positioned therein, ports in said chamber, a valve operated by said latter pneumatic between said latter ports, an exhaust device communicating with both of said. chambers, an airvconduit tapped into said smaller chamber, a, finger piece positioned upon the free end of said conduit and having an opening therethrough and adapted to be closed by the finger of the operator and said primary pneumatic brought into action by the closing of said opening for closing communication between the first named pneumatic and the atmos phere and establishing communication between sueh pneumatic and the exhaust device.

In combination with damper, pedal and damper operating rod connected to the pedal of a self-playing piano, a pneumatic normally distended by communication with the atmosphere, a connection between for operating the latter when the pneumatic is deflated, an exhaust device, a movable member having an air port therein normally open to the atmosphere and adapted to'be closed by the finger of the operator and pneumatic means brought into action by the closing of said port for closing communieation between the first named pneumatic and the atmosphere and establishing communication between such pneumatic and the exhaust device.

In witness whereof I have hereunto set my hand th s 27th day of February 1906.

LEWIS l3. DOMAN.

pneumatic last named the strings,

Nn'rrin A. BIBBIN s.

the pneumatic and pedal 

